1. Field of the Invention
The invention relates to a baking oven comprising a housing having side walls; at least one hearth formed in the housing and defined by the side walls thereof; a driving roller provided at one end of each hearth; a deflection roller provided at the other end of each hearth; a baking conveyor belt guided over the driving roller and the deflection roller; two bearings for at least one roller which are provided on the outsides of the housing and displaceable in a horizontal direction of displacement in the lengthwise direction of the respective hearth; a recess formed in each side wall and penetrated by the displaceable roller and adjusted to a maximal length of displacement of the roller; and a sealing arrangement for sealing the recess in each position of displacement of the roller.
2. Background Art
In baking ovens of the generic type, which are regularly multi-deck baking ovens of comparatively great length, the temperature dependent expansions of the housing on the one hand and of the baking conveyor belt on the other vary considerably. For this reason the deflection roller or the driving roller, as a rule the deflection roller, must be displaceable in the lengthwise direction of the respective hearth. Since the bearings of the respective roller are disposed out of the hearth, i.e. on the outside of the side walls of the housing, a recess must be available in the side wall, through which the roller or a corresponding shaft section thereof is extended outwards and in which it is displaceable in the lengthwise direction of the respective hearth. Since the dough pieces must be treated with vapor at the beginning of the baking process, i.e. directly after feed, it is necessary that this vapor is retained for a certain time in the respective baking chamber. Any uncontrolled escape of vapor through the mentioned recesses would lead to drawbacks in baking implementation and must be precluded. Filling up the recesses with a packing of insulating material as tried in practice did not give satisfying results; moreover, the vapor precipitates in this insulating material, leading to thorough moistening. Furthermore, the space available in the direction of displacement of the roller is strongly restricted.